Why can't we have this you ask? Well the builder says no and they don't have to give a reason. My guess is that it could be because the concrete needs to be 32 hards (32 MPa) for polishing otherwise it may fall apart while being polished. This is over and above the minimum which volume builders tend to stick too. Curing time may also have something to do with it.
There is hope of retrofitting a polished concrete look by laying a small layer of 90 hards concrete over the top of the cheap stuff and polishing that. At $120 a square meter for 13 Hiperfloor polishes and then the price of the 90 hards concrete on top of that, it's a bit too much expense at the moment. Maybe when we hit the jackpot on the pokies we'll re-consider.